CBHVAC wrote:
Its a two stage outdoor unit, and if you have electric backup, or other form
of backup heat, its a three stage.

no electric backup as I have year round temps above 15 Celsius (mostly at 30 C and
higher)

If the outdoor unit is wired to bring both compressors online at the same
time, and have a form of backup heat, its only two stage.

it's wired to run first compressor for up to 30 min and then start 2nd compressor if
desired temp is not reached
also, the temp differential is set to 1 degree + 1 degree (ie. start unit-1 if temp is
hotter by 1 degree than desired setting and run also unit-2 if 2 or more degrees
difference)

so, I suppose that answers it should be setup as 2-stage heat pump, thanks